[CALCITE-3142] NullPointerException when rounding a nullable numeric

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 1.20.0
• Fix Version/s: 1.24.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Feng Zhu
• Reporter: Mohamed Mohsen
• Created: 22/Jun/19 20:36
• Updated: 28/May/21 10:12
• Resolved: 26/Jun/20 17:19

Description

The following query throws a NPE in the generated code because it assumes the divided value to be an initialized Java object (Not null), which is fine for the first row, but not for the second.

SELECT ROUND(CAST((X/Y) AS NUMERIC), 2) FROM (VALUES (1, 2), (NULLIF(5, 5), NULLIF(5, 5))) A(X, Y)

If I modify the query a little bit, it runs ok:
– No casting

SELECT ROUND((X/Y), 2) FROM (VALUES (1, 2), (NULLIF(5, 5), NULLIF(5, 5))) A(X, Y)

– No rounding

SELECT (X/Y)::NUMERIC FROM (VALUES (1, 2), (NULLIF(5, 5), NULLIF(5, 5))) A(X, Y)

This is the optimized generated code

final Object[] current = (Object[]) inputEnumerator.current();
final Integer inp0_ = (Integer) current[0];
final Integer inp1_ = (Integer) current[1];
final java.math.BigDecimal v1 = new java.math.BigDecimal(
  inp0_.intValue() / inp1_.intValue()); // <<< NPE
return inp0_ == null || inp1_ == null ? (java.math.BigDecimal) null : org.apache.calcite.runtime.SqlFunctions.sround(v1, 2);

This is the non-optimized one

final Object[] current = (Object[]) inputEnumerator.current();
final Integer inp0_ = (Integer) current[0];
final boolean inp0__unboxed = inp0_ == null;
final Integer inp1_ = (Integer) current[1];
final boolean inp1__unboxed = inp1_ == null;
final boolean v = inp0__unboxed || inp1__unboxed;
final int inp0__unboxed0 = inp0_.intValue(); // <<< NPE
final int inp1__unboxed0 = inp1_.intValue(); // <<< NPE
final int v0 = inp0__unboxed0 / inp1__unboxed0;
final java.math.BigDecimal v1 = new java.math.BigDecimal(
  v0);
final java.math.BigDecimal v2 = v ? (java.math.BigDecimal) null : org.apache.calcite.runtime.SqlFunctions.sround(v1, 2);
return v2;

Issue Links

• duplicates: CALCITE-3224 New RexNode-to-Expression CodeGen Implementation
• is duplicated by: CALCITE-3832 NPE when decimal cast double
• is related to: CALCITE-3143 Dividing by NULLIF may cause "ArithmeticException: Division by zero"
• is related to: CALCITE-3832 NPE when decimal cast double
• relates to: CALCITE-3150 NullPointerException when UPPER is repeated and combined with LIKE
• relates to: CALCITE-3173 RexNode Code Generation Problem
• links to: GitHub Pull Request #1316
• links to: GitHub Pull Request #1347